This invention relates to a slot forming tool that simultaneously forms two opposed flaps In a channel of a wall frame to create a consistently shaped slot for aligning, slidingly receiving and snap fitting a support stud in place during an intermediate stage of construction of the wall frame.
Modern building construction techniques use a number of relatively economical components to efficiently form the interior walls of a building. The wall frames typically include fabricated sheet metal components that can be easily cut to length in the field when necessary. As shown in FIG. 1, the frame includes upper and lower U-shaped support channels that are anchored to the ceiling and floor, respectively. The frame also includes a number of hollow C-shaped studs that span between the upper and lower channels at evenly spaced locations down the length of the channels. Once the wall frames are erected, the electrical wiring, plumbing, ventilation ducts, insulation, and other desired components and materials are routed through or placed within the wall frames. Drywall or paneling is then secured to the sides of the wall frames to complete the walls of the building.
The bottom ends of the studs are typically bolted or otherwise rigidly secured to the lower channel. However, in many wall constructions, the top end of the studs are not rigidly secured to the upper channel. The upper channel is anchored to the ceiling, but is not designed to rest on the studs. This type of construction enables the ceiling to move vertically or xe2x80x9cfloatxe2x80x9d above the wall. When the ceiling flexes do to an increase in load, such as by adding equipment, people or snow, the ceiling will not compress, crush or buckle the studs, drywall, paneling or other components and materials forming the wall.
During the construction of the interior walls, the wall frames are first erected to an intermediate stage of construction. During this interim stage, the upper and lower channels are anchored to the ceiling and floor, respectively, and the ends of the studs are fixed to the channels. The ends of the studs may be fixed to the channel via friction, as the studs and channels are about the same width, or the studs may be screwed or riveted to the channels at their desired locations. Electrical conduit and outlets, plumbing, heating and ventilation ducts, are then routed throughout the rooms of the building. Each stud includes one or more knockouts to allow these components to be easily routed through the stud and the wall frame. As shown in FIG. 1, the construction personnel performing this work can inadvertently bump or intentionally move the studs from their intended positions. If the studs are screwed or riveted in place, they are difficult to move and may be bent by the workers. Before the wall is completed, the fasteners securing the studs to the upper channel must be removed. If the studs are simply held in place by friction, the workers can easily move them, but the workers must take the time to realign the studs into their intended evenly spaced positions.
The acoustical or thermal insulation is then packed into the wall frame. This packed insulation will maintain the spacing and alignment of the upper end of the studs even though they are not rigidly secured to the upper channel. Once this insulation is installed, it is difficult to reposition the support studs if they are out of their desired vertical, evenly spaced positions. The electrical, plumbing and duct work will invariably result in the necessary repositioning of some studs. Still, many studs are left out of their desired position because the workers cannot easily realign them. Packing insulation between the studs can also move the studs out of position. The quick pace of modern building construction and the division of tasks aggravate this problem, so that no person or group of workers is responsible for maintaining the alignment of the studs. The end result is that the studs are often left out of place and are difficult to locate once the drywall or paneling is installed.
A problem with temporarily riveting or screwing the studs to the upper channel to maintain the desired stud alignment is that these fasteners need to be removed before the drywall or paneling is mounted to the wall frame. This is a time consuming and monotonous task. Workers can easily forget to remove one or more of the hundreds of fasteners securing the studs to the upper channel throughout the building. The wall frame is then improperly fixed to the ceiling, which can crush or buckle the studs, drywall, paneling or other wall components.
Many architects and contractors specify that slots be formed in the upper channels to align the studs without fastening them to the upper channel during the intermediate stage of construction, as shown in FIG. 2. For reasons discussed below, the bottom ends of the studs remain secured to the lower channel via friction, rivets or screws. Each slot is formed by two inwardly bent folds that abut the sides of the stud to retain the stud in its desired position. Because the studs and channel are about the same width, each stud is twisted axially to allow it to snap-fit into its corresponding slot. The twisting causes the open side of the C-shaped stud to compress so that that it will clear one of the inwardly bent folds. The studs are removed the same way. The ability to simply twist the studs to insert or remove them renders their installation or removal a relatively quick and easy task. Should an electrician, plumber or duct worker bump or temporarily move a stud out of position while performing his or her work, the worker can easily reposition the stud into its slot at the desired location. A slot having a width that is xe2x85x9 inch larger than the width of the slot will produce this snap-fit, without causing the stud to bind with the upper channel when the wall is complete.
A problem with using slots to align and hold the studs in a wall frame is that hundreds of slots must be individually formed by hand at the construction site. Each slot requires two cuts at spaced locations to form separate vertical slits. The worker must also inwardly bend the channel to form each fold. To achieve a rectangular fold, the worker must also cut or tear the sheet metal horizontally at the end of each slit, as shown in FIG. 2a. Accordingly, these slots are labor intensive and costly to form.
Another problem with conventional slot forming methods is that the slots are inconsistently sized and shaped. Hand forming each slot produces inconsistencies in slot width and fold shape. These inconsistencies inhibit the formation of each slot to ensure that each stud properly snap-fits in place. The slits are often cut at varying distances apart, and some slits are inevitably cut angled out of vertical so that they are not parallel. The folds will also have different widths depending on where the worker grips the channel with the pliers relative to the slit. The folds are also bent to different angles relative to the rest of the channel. The result is a lack of uniformity in fold geometry and slot width. Slots often have different slot widths, such as widths a, b and c, as shown in FIG. 2. One slot is too narrow, while another is too wide. Yet, a narrow slot will not receive a stud, or it will hold the stud too tightly so that it cannot be easily inserted or removed. Narrow slots can also cause the studs to bind against the upper channel during use, which can damage the stud and wall. A slot that is too wide will not properly retain the stud, so that the stud can fall out or be easily bumped out of its slot.
A further problem is that the slits are not made to a consistent length or depth. Slits that are too long will unnecessarily weaken the channel. Slits that are too short will create folds that are not strong enough to retain the stud.
A still further problem with forming the slots is that at least two different hand tools are needed to create each slot. First, a cutting tool is used to cut the sides of the channel at the desired locations for the two slits. Once the slits are cut, a second hand tool such as a pair of pliers is used to bend and tear the channel to form two inwardly bent folds. The worker must pick up, use, and put down each tool hundreds of times. If the worker makes all the slits first and later comes back to bend each of the folds, the worker must retrace his or her path through the entire building. This effectively doubles the amount of work they must perform.
A still further problem in forming slots into the channel is that conventional bending tools, such as a pair of pliers, do not enable a worker to easily bend and tear the folds to a consistent shape or geometry. A conventional pair of pliers has no guide to align and grip the sheet metal a specific distance from an adjacent slit. As a result, some folds are wider than others. A conventional pair of pliers also has no guide to enable the worker to correctly tear the channel to form a rectangular fold having a specific width, or bend the fold to a consistent angle relative to the vertical side of the channel. Accordingly, the shape or geometry of the folds and the width of the slots will vary.
A still further problem in forming the slots is that they are not efficiently formed by conventional cutting and bending tools. The worker must first align the cutting tool perpendicular to the vertical side of the channel, and then cut the side to an appropriate depth. The desired distance between the cuts of each slot must be measured prior to making the second cut. The worker must then pick up a bending tool to form the folds. The folds must be shaped to the same desired geometry and bent to the same desired angle. These steps must be repeated several hundred times. Each step takes time, and adds to the cost of the wall.
A still further problem with many conventional cutting tools is that they are difficult to use to cut the metal channel. A tool with small handles will require a great deal of hand strength to make the cuts in thicker gauge channels. A worker can become fatigued making the hundreds of cuts needed to form the channels throughout the building, particularly for thicker gauge channels, and can lead to inconsistencies in the formation of the slots. Yet, a tool with long handles can be unwieldy, especially when the slots are being formed in an upper channel several feet above the worker. The worker can easily crush the channel when aligning or stroking the tool, particularly for thinner gauge channels.
A still further problem with many conventional cutting tools is that their blades will quickly dull when cutting thicker gauge channels. The cutting blades cannot be easily removed and replaced with sharp blades. Instead, the entire tool must be set aside for sharpening or discarded. Thus, the costs associated with using these types of cutting tools is needlessly inflated.
The present invention is intended to solve these and other problems.
The present invention relates to a slot-forming tool for forming a number of consistently sized and shaped slots in a channel of a wall frame. Each slot aligns and slidingly supports a vertical stud that is snap-fit in place during an intermediate stage of constructing a wall. The tool has an arm for aligning the tool against the channel and a pivotally connected arm that is stroked to form the slot in the channel, Each arm has a gripping portion, an intermediate connecting portion and a working portion. The working portion of the alignment arm includes a cutting block with a face and two spaced sidewalls that form a pair of cutting edges. The working portion of the pivoting arm includes a pair of spaced knives. Each knife has a ramp or wedge shaped blade with a cutting edge that is aligned to shearingly engage one of the cutting edges of the cutting block and slide down the sidewall of the cutting block a predetermined distance. During use, the arms are pivoted apart to an open position to align the cutting block with the channel where a slot is to be formed. As the pivoting arm is stroked to its closed position, the tool simultaneously cuts two parallel slits and simultaneously forms two roughly perpendicular tears in the channel to form a pair of opposed flaps. The same stroke also bends the flaps inwardly into the channel to form the slot. Each stroke of the tool creates one consistently sized and shaped slot for receiving a stud via a snap-fit. Because the upper track channel of many wall frames are designed to remain free to move vertically or xe2x80x9cfloatxe2x80x9d with respect to the studs, the slots and flaps must be sized and shaped so that the flaps do not bind against the stud. The flaps can be formed to a number of shapes, such as a rectangular or triangular shape to accommodate a particular design.
An advantage of the slot forming tool of the present invention is that it allows workers to properly and consistently form slots in the channels of a wall frame to align and slidingly support the studs during an intermediate stage of constructing a wall. A single stroke of the tool completely forms each slot. During each stroke, the tool cuts, tears and bends the channel to properly form the two spaced flaps that give the slot its size and shape. Each of the hundreds of slots is properly and consistently formed because the tool does each task in a single stroke. The slots eliminate the time consuming and monotonous task of installing and removing screws or rivets from the upper channel. The tool properly cuts and forms each slot so that binding between the studs and the upper track is avoided. The ceiling remains free to flex without crushing or buckling the studs, drywall, paneling or other wall components during the life of the building.
Another advantage of the slot forming tool is that it is adjustable to form differently shaped slots. The tool can be set to form flaps with different shapes, such as a rectangular or triangular shape. The adjustability of the alignment mechanism, blade angle and thickness and stop point of the closed position give the tool the ability to form customized slots for a particular wall construction or building design.
A further advantage of the slot forming tool is that it forms consistently sized and shaped slots. Once the tool is adjusted to produce a specific slot geometry, the tool forms each slot to that same geometry. Each slot has the same width and flap shape to achieve a proper snap-fit with each stroke of the tool. Parallel slits are cut equidistantly apart each time. The tool has an alignment mechanism that abuts the channel to properly position the cutting blades so that each flap has the desired geometry. The properly formed slots slidingly retain the studs, so that they will not fall out or be easily bumped out of their slot, and they will not bind against the upper channel during use.
A still further advantage of the slot forming tool is that it consistently cuts vertical slits down the side of a channel to a desired length or depth. The slits are correctly sized to avoid unnecessary weakening of the channel while creating flaps that are strong enough to retain the stud.
A still further advantage of the slot forming tool of the present invention is that only one tool is needed to form each slot. The workers do not need to go through the inefficient and monotonous task of picking up, using and putting down several tools each time a slot is formed. Instead, a single stroke of the slot forming tool completely forms a slot, thereby dramatically decreasing the amount of work that a worker must perform to create the hundreds of slots throughout a building.
A still further advantage of the slot forming tool is that a worker can easily bend and tear the folds to a consistent shape and geometry. The slot forming tool has a set closed position. When the tool is stroked to this closed position, the ramp shaped blades cut, tear and bend the channel so that each flap is inwardly bent a desired distance from the remaining portion of the channel. As a result, the shape or geometry of each flap and the width of each slot is constant.
A still further advantage of the slot forming tool is that the slots are efficiently formed. The worker uses the alignment mechanism to align the cutting block against the sidewall of the channel. The alignment mechanism ensures that the ramped blades are consistently aligned to a desired depth down the sidewall of the channel. The alignment mechanism positions the tool against the base of the channel without crushing the sidewall of the channel. The worker then simply strokes the tool to form the slot. A single stroke forms each slot. Accordingly, the tool can efficiently produce the hundreds of slots needed to assembly the various wall frames throughout the building.
A still further advantage of the slot forming tool of the present invention is that it is easy to use to cut thick and thin gauge metal channels. The arms of the slot forming tool are sufficiently long to enable a worker to form the slots with only modest amount of hand and arm strength. The tool is also symmetrically designed to produce a balanced feel that is particularly helpful when the tool is held overhead to form slots in the upper channel of a wall frame. This design allows a worker to easily form hundreds of slots in the channels throughout the building without fatigue and without damaging the channels. The tool provides a better working environment for the workers and enables them to produce better quality work.
A still further advantage with the slot forming tool of the present invention is that the ramped blades can be quickly replaced when they become dull, or to adjust the tool to form a different slot size or geometry. The blades can be quickly and easily removed and replaced at the job site. The tool does not need to be set aside for sharpening or discarded when the blades become dull. Accordingly, the costs associated with the tool are kept to a minimum.
Other aspects and advantages of the invention will become apparent upon making reference to the specification, claims and drawings.